I have a cross metal piece near the top of the drain and I have hair buildup between the cross and the trap. Is the top of the drain a threaded piece? If so , what tool do I use to take it apart? I can't fit a bent wire down through the X. Hope this is clear.

"I have a cross metal piece near the top of the drain and I have hair buildup between the cross and the trap. Is the top of the drain a threaded piece? If so , what tool do I use to take it apart?"

They make a tub drain removal tool, (see image) to take the tub drain out and yes, it's threaded. Good luck, Tom

Do not remove the tub drain basket. It may leak or be broken doing this. Use a wet vac on the crosshair part and bend a small hook on the coathanger to dig it out.