The FR5xx chips don't use BCS or BCS2. There's a completely different clock infrastructure called CS.
Though the header is probably located within your CCS installation at something like ccs-5.2.1/ccsv5/ccs_base/msp430/include/msp430fr5739.h, you need to look at the FR5XX family user's guide (which is different from the 5xx6xx family user's guide). Find slau272; the latest rev is slau272a. I find google for "slau272" to work.
If you need examples other than those provided by TI, BSP430 has support for this peripheral; see http://pabigot.github.com/bsp430/cs_8h.html and the source under git.
There has been alot of good questions going on in the past few weeks - accompanied with very good discussions. One way you can show your appreciation is by using the "Thanks" or "Thumbs up " button on the top right. It may be hard to notice but a screenshot always helps:
Use it if you have received something useful from a member. It takes time to write those posts and code. Consider it as karma, that's as good as it can get. :mrgreen: