Just hit the little "plus" button top right corner and it will pop up the list of your companions.Is it no longer possible to leave your companions behind? Usually you could talk to them via the party screen in a town or castle and tell them to stay there. Currently the "Talk" button is no longer available if you stay in a castle or town and use the party screen.
Talk to them to take them back.
Or click on their image when in tavern menu and hit "take back to party".