I see that is working in 5.7 and to make it work in 5.6 here is the solution I found.

I contributed this XML in Advanced Settings > XML Extensions

 <extension target="org.nuxeo.ecm.platform.forms.layout.WebLayoutManager"
    point="layouts">
   <layout name="faceted_search_default_selectors">
      <templates>
        <template mode="any">
          /layouts/layout_faceted_search_default_actions_template.xhtml
        </template>
      </templates>
      <rows>
        <row>
          <widget>faceted_searches_selector</widget>
        </row>
        <row>
          <widget>saved_faceted_searches_selector</widget>
        </row>
      </rows>
    </layout>

    <layout name="faceted_search_default_actions">
      <templates>
        <template mode="any">
          /layouts/layout_faceted_search_default_actions_template.xhtml
        </template>
      </templates>
      <rows>
        <row>
          <widget>actions_bar</widget>
        </row>
      </rows>
    </layout>
</extension>

Then I added this following layout in Resources > Layouts

Finally I added this as first Widget in my content view form

Generic Widget
  Hide Label: checked
  Fields: #{layoutValue}
  Widget Type: layout
  layout mode: search
  custom property configuration: name / faceted_search_default_selectors

And as last widget in my content view form

Generic Widget
  Hide Label: checked
  Fields: #{layoutValue}
  Widget Type: layout
  layout mode: search
  custom property configuration: name / faceted_search_default_actions

Hope this will help someone else.