Well mac Tools are Limited, Book Designer
https://www.mobileread.com/forums/showthread.php?t=11786 is the best tool that i have for book formatting. but its windows only, run it in a virtual box i guess.
book creator tool should work if you have Microsoft word
https://www.mobileread.com/forums/showthread.php?t=28313
but i find it to be much more manually intesive, and didnt like it nearly as much as book designer.