How to access a subquery in an active record association object?

gistfile1.rb

# we have a query like this one:
# but in some cases it will return duplicate records because of the joins
subquery = Workspace
  .joins(:workspace_roles)
  .where('workspace_roles.role_id IN (?)', role_ids)
  .joins(:workspace_locations => :location)
  .where('workspace_locations.location_id IN (?)', location_ids)
  .where('locations.active = 1')
 
# on in order not to return duplicates we do the following:
subquery = Workspace
  .select(:id)
  .joins(:workspace_roles)
  .where('workspace_roles.role_id IN (?)', role_ids)
  .joins(:workspace_locations => :location)
  .where('workspace_locations.location_id IN (?)', location_ids)
  .where('locations.active = 1')
  
query = Workspace.where(id: subquery)
 
# A class returns this active record asssociation
# after this query has been created I want to attach conditions to the subquery
How can I get access to it?
 
query = query.some_way_to_access_subquery.where('locations.language_id IN (?), language_ids)