Adding TAGS to a template search
Design and Skin Customization
The problem here is that you have THREE "search1" parameters, so the next is overwriting the previous - try this:
{jrSeamless_list modules="jrVideo,jrYouTube" order_by="_item_id desc" search1="youtube_category = football" search2="*_tags like %5th% || *_tags like %6th%" pagebreak=15 page=$_post.p pager=false template=$tpl}
Note how I use an OR condition in the search2 parameter, and each search parameter is incremented by one (i.e. search1, search2, search3 and so on). I also changed the order_by from _created to _item_id - ordering by _item_id is the same as _created but faster.
Let me know if that works.