May have to search through info on the surrounding battle field areas such as Chicamauga, Lookout and Signal. Can't remember seeing anything Tunnel Hill specific.
Try Jeff Shaara's The Smoke at Dawn. Covers the time from the end of Chickamauga to Missionary Ridge to Cleburne's defense of Tunnel Hill and the retreat toward Dalton. There's a good many maps.
Hey man if you find anything good post some pics. I have family up in that area and want to start detecting when I'm up there visiting. I'm also gonna start checking around the Athens area. I have some friends there that live on a farm that we visit a couple times a year. Might start doing some detecting there as well.
I have "The Civil War Battlefield Guide" from The Conservation Fund by Frances Kennedy. Has lots of maps.
You can buy these sorts of books cheap off Ebay or at thrift stores, Goodwill, etc. You can afford to buy a lot of books when they are .50 cents to $4.00