Which version of AE are you using?
To open two comp viewers (in CS3 and CS4):
1) Open one of the comps, doesn't matter which one.
2) Click on the tab text and select Locked.
3) Double click on the other comp.
4) Click on the grabby widget and drag the panel straight down to subdivide the comp area.
5) you should now be able to get the other comp visible in the right side.
Thanks for the advice,
What I'm trying to do,however,is put the text sequence on top of the image sequence.It's like in Photoshop when you flatten layers and then put one on top of the other is the only comparison I can make.
I can't open the text layer/composition without leaving blank the new footage sequence I've created I think because they both come from the same original composition.
I want to create one composition for the text and a completley different one for the footage then I can simply put comp 1 on top of comp 2 and bingo...
I'm sorry, but I'mk really confused as to what you are actually trying to do. My best guess is, that you simply may need to cut&paste your layers from some parent comp that obviously stil lsomehow references both teh background and text, into a clean, new one. In case of such issues it helps to study the flowchart view, so give that a spin. also the miniflow in CS4 (shortly tap Shift) would serve the same purpose.