diff --git a/.ruby-gemset b/.ruby-gemset
index eedd89b..fcf5595 100644
--- a/.ruby-gemset
+++ b/.ruby-gemset
@@ -1 +1 @@
-api
+api-v2
diff --git a/.ruby-version b/.ruby-version
index 324db8d..4e34c4d 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-ruby-2.6.8
+ruby-2.7.6
diff --git a/Gemfile b/Gemfile
index 88ac8b9..4170559 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ gem 'rails', '~> 6.0.2'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+gem 'puma', '>= 5.6'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 # gem 'jbuilder', '~> 2.5'
 # Use Redis adapter to run Action Cable in production
diff --git a/Gemfile.lock b/Gemfile.lock
index c38a145..3f1cd9c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -69,7 +69,7 @@ GEM
     globalid (1.0.0)
       activesupport (>= 5.0)
     http-accept (1.7.0)
-    http-cookie (1.0.4)
+    http-cookie (1.0.5)
       domain_name (~> 0.5)
     i18n (1.10.0)
       concurrent-ruby (~> 1.0)
@@ -96,7 +96,8 @@ GEM
     nokogiri (1.13.6)
       mini_portile2 (~> 2.8.0)
       racc (~> 1.4)
-    puma (3.12.6)
+    puma (5.6.4)
+      nio4r (~> 2.0)
     racc (1.6.0)
     rack (2.2.3)
     rack-test (1.1.0)
@@ -168,7 +169,7 @@ DEPENDENCIES
   bootsnap
   byebug
   listen (>= 3.0.5, < 3.2)
-  puma (~> 3.7)
+  puma (>= 5.6)
   rails (~> 6.0.2)
   rest-client (>= 2.1.0.rc1, < 2.2)
   spring
diff --git a/app/services/search_item_req.rb b/app/services/search_item_req.rb
index e9260c0..e298836 100644
--- a/app/services/search_item_req.rb
+++ b/app/services/search_item_req.rb
@@ -51,6 +51,8 @@ def build_request
 
     # add bool to request body
     req["query"]["bool"] = bool
+    # uncomment below line to log ES query for debugging
+    # puts req.to_json()
     return req
   end
 
@@ -84,7 +86,6 @@ def facets
     Array.wrap(@params["facet"]).each do |f|
       # histograms use a different ordering terminology than normal aggs
       f_type = type == "_term" ? "_key" : "_count"
-
       if f.include?("date") || f[/_d$/]
         # NOTE: if nested fields will ever have dates we will
         # need to refactor this to be available to both
@@ -104,7 +105,70 @@ def facets
             "order" => { f_type => dir },
           }
         }
-      # if nested, has extra syntax
+      #nested facet, matching on another nested facet
+      
+      elsif f.include?("[")
+        # will be an array including the original, and an alternate aggregation name
+      
+
+        options = JSON.parse(f)
+        original = options[0]
+        agg_name = options[1]
+        facet = original.split("[")[0]
+        # may or may not be nested
+        nested = facet.include?(".")
+        if nested
+          path = facet.split(".").first
+        end
+        condition = original[/(?<=\[).+?(?=\])/]
+        subject = condition.split("#").first
+        predicate = condition.split("#").last
+        aggregation = {
+            # common to nested and non-nested
+            "filter" => {
+              "term" => {
+                subject => predicate
+              }
+            },
+            "aggs" => {
+              agg_name => {
+                "terms" => {
+                  "field" => facet,
+                  "order" => { type => dir },
+                  "size" => size
+                },
+                "aggs" => {
+                  "field_to_item" => {
+                    "reverse_nested" => {},
+                    "aggs" => {
+                      "top_matches" => {
+                        "top_hits" => {
+                          "_source" => {
+                            "includes" => [ agg_name ]
+                          },
+                          "size" => 1
+                        }
+                      }
+                    }
+                  }
+                }
+              }
+            }
+          }
+        #interpolate above hash into nested query
+        if nested
+          aggs[agg_name] = {
+            "nested" => {
+              "path" => path
+            },
+            "aggs" => {
+              agg_name => aggregation
+            }
+          }
+        else
+          #otherwise it is the whole query
+          aggs[agg_name] = aggregation
+        end
       elsif f.include?(".")
         path = f.split(".").first
         aggs[f] = {
@@ -161,8 +225,43 @@ def filters
     # (type 2 will only be used for dates)
     filters = fields.map {|f| f.split(@@filter_separator, 3) }
     filters.each do |filter|
-      # NESTED FIELD FILTER
-      if filter[0].include?(".")
+      # filter aggregation with nesting
+      if filter[0].include?("[")
+        original = filter[0]
+        facet = original.split("[")[0]
+        nested = facet.include?(".")
+        if nested
+          path = facet.split(".").first
+        end
+        condition = original[/(?<=\[).+?(?=\])/]
+        subject = condition.split("#").first
+        predicate = condition.split("#").last
+        term_match = {
+          # "person.name" => "oliver wendell holmes"
+          # Remove CR's added by hidden input field values with returns
+          facet => filter[1].gsub(/\r/, "")
+        }
+        term_filter = {
+          subject => predicate
+        }
+        if nested
+          query = {
+            "nested" => {
+              "path" => path,
+              "query" => {
+                "bool" => {
+                  "must" => [
+                    { "match" => term_filter },
+                    { "match" => term_match }
+                  ]
+                }
+              }
+            }
+          }
+        end
+        filter_list << query
+      #ordinary nested facet
+      elsif filter[0].include?(".")
         path = filter[0].split(".").first
         # this is a nested field and must be treated differently
         nested = {
diff --git a/app/services/search_item_res.rb b/app/services/search_item_res.rb
index a82a199..05210e7 100644
--- a/app/services/search_item_res.rb
+++ b/app/services/search_item_res.rb
@@ -18,7 +18,6 @@ def build_response
     # strip out only the fields for the item response
     items = combine_highlights
     facets = reformat_facets
-
     {
       "code" => 200,
       "count" => count,
@@ -66,7 +65,7 @@ def format_bucket_value(facets, field, bucket)
     # dates return in wonktastic ways, so grab key_as_string instead of gibberish number
     # but otherwise just grab the key if key_as_string unavailable
     key = bucket.key?("key_as_string") ? bucket["key_as_string"] : bucket["key"]
-    val = bucket["doc_count"]
+    val = bucket.key?("field_to_item") ? bucket["field_to_item"]["doc_count"] : bucket["doc_count"]
     source = key
     # top_matches is a top_hits aggregation which returns a list of terms
     # which were used for the facet.
@@ -89,8 +88,7 @@ def reformat_facets
       facets = {}
       raw_facets.each do |field, info|
         facets[field] = {}
-        # nested fields do not have buckets at this level of response structure
-        buckets = info.key?("buckets") ? info["buckets"] : info.dig(field, "buckets")
+        buckets = get_buckets(info, field)
         if buckets
           buckets.each { |b| format_bucket_value(facets, field, b) }
         else
@@ -110,4 +108,18 @@ def remove_nonword_chars(term)
     transliterated.gsub(/<\/?(?:em|strong|u)>|\W/, "").downcase
   end
 
+  def get_buckets(info, field)
+    buckets = nil
+    # ordinary facet
+    if info.key?("buckets")
+      buckets = info["buckets"]
+    # nested facet
+    elsif info.dig(field, "buckets")
+      buckets = info.dig(field, "buckets")
+    # filtered facet
+    else
+      buckets = info.dig(field, field, "buckets")
+    end
+    buckets
+  end
 end
diff --git a/config/environments/development.rb b/config/environments/development.rb
index 1e22e09..14a0a40 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -61,4 +61,5 @@
   # CDRH CONFIGURATION
 
   config.hosts << "cdrhdev1.unl.edu"
+  config.hosts << "whitman-dev.unl.edu"
 end