How to do multi selects in Ecto

unfortunately I didn’t understand what you said, I’m sorry.
version.title is a string field and version_id relationed with record table, In fact, this is a filter, if it doesn’t answer me, so what do I do? I’m confused.
I just need to get table records which relation with Version table in the Category concerned( category id = 2) . how can I do? I’m new to this field , I sorry and thank you for giving me your time.