Pull Up is a well known compound exercise for training back. It mostly targets Latissimus Dorsi (Lats) but some other back muscles and biceps are also training. Since it only needs fixed bar (or pull up bar), you may perform that exercise at home or outdoor.
Doesn’t hurt to try out exercise variations. Here is one: How to do a bicep concentration curl exercise from the side using dumbbells. Let us know how it goes.
A powerful demonstration of the best bicep exercises – with some that workout the triceps and chest too.