Just the one version of the research tree as far as I am aware, I suggest you reach out to support.
The first ancient wonders are unlocked at the end of chapter 4, you can then upgrade those wonders using kp or runes to a max of level 30 or 35 dependant on wonder. AW buildings come in pairs at the end research(es) of each chapter from 4+ to 20.
Level and chapter are 2 different things.
There are currently 20 chapters in the game, general buildings can be upgraded to certain levels as you progress, with the exemption of buildings won in events, this can get complicated as some event buildings can be evolved from level 1 to 10, a separate thing again.