Finding image files packed in file types. (binary) (.as7 containing images of .tm2 ps2 format)

Whilst using the Hex editor what does one search for if there explore a file for potential images packaged inside? Header types, I’m not too keen on programming, but I’m here to learn and once I do I can continue to grow. I have a specific file that I believe has images with the file type tim2 (ps2 image) packaged inside. The file type I’m dealing is .as7. Any aid is appreciated thank you.

this is .as7 in question:

Without a doubt there are 12 .tm2 images lurking in it’s contents (after searching for the .tm2 TIM2 header: 54 49 4D 32, needless to find the images’ bit depth to (at least) be viewable in either the rainbow tool: ( or OPTPIX image Studio. Grabbing the bytes from the first .tm2 start to the end gives an illegal bit depth error in such tools above; but this file in particular is indeed read by the game in question so it’s certainly there.