title: NEST Conditional filter query with multiple terms
body: <p>I would like to do a ElasticSearch query like this:</p>
  
  <pre><code>{
      "query" :
      {
          "bool" :
          {
              "filter" : [
                  {
                      "terms" :
                      {
                          "name" : ["name1", "name2"]
                      }
                  },
                  {
                      "terms" :
                      {
                          "color" : ["orange", "red"]
                      }
                  }
              ]
          }
      }
  }
  </code></pre>
  
  <p>I've tried to implement it in NEST like this:</p>
  
  <pre><code>_elasticClient
      .SearchAsync&lt;MyDocument&gt;(s =&gt;
          s.Index("myindex")
              .Query(q =&gt; q
                  .Bool(bq =&gt; bq
                      .Filter(fq =&gt;
                      {
                          QueryContainer query = null;
  
                          if (nameList.Any()) {
                              query &amp;= fq.Terms(t =&gt; t.Field(f =&gt; f.Name).Terms(nameList));
                          }
  
                          if (colorList.Any()) {
                              query &amp;= fq.Terms(t =&gt; t.Field(f =&gt; f.Color).Terms(colorList));
                          }
  
                          return query;
                      })
                  )
              )
      );
  </code></pre>
  
  <p>But that gives me a query like this where the filters are wrapped inside a <em>bool must</em>:</p>
  
  <pre><code>{
      "query" :
      {
          "bool" :
          {
              "filter" : [
                  {
                      "bool" :
                      {
                          "must" : [
                              {
                                  "terms" :
                                  {
                                      "name" : ["name1", "name2"]
                                  }
                              },
                              {
                                  "terms" :
                                  {
                                      "color" : ["orange", "red"]
                                  }
                              }
                          ]
                      }
                  }
              ]
          }
      }
  }
  </code></pre>
  
  <p>How should I change my NEST code to give me the right query? Do have have to add my terms to something other then a <em>QueryContainer</em>?</p>