You have to get years in experience without becoming older mentally.
Take any chance you get, say "yes I can" and just do it.
I would never ask others such a question, if I am not able to take the decision alone then I already lost.
The FI guy would tell FI is the best, the SD guy says SD, the CRM guy CRM, this would not really help me (the MM guy says do one of the other suggestions, then I have less competitors 
)
I actually do not believe that it would boost my career if I choose something where I am not 100% convinced that it fits me, that I like to do it for many years.
You have to ask yourself what your target is, what you understand as "career" . Want become a boss? or THE expert, THE generalist, or just make money?
I am not an example for others, I never dreamed about a career, I just want like my job, want have the liberty to do it like I want do it, which gives me enough money to shape my life.
I just let me drift and float, started as accountant, created functional designs, learned debugging and reading program code, programmed then myself, changed to IT, became a system operator, implemented purchasing module, supported it, was then helping to built up a new company implementing all modules with a small team, supported it, was then asked to go to the US to design SAP, did rollouts in Europe added WM skills, then worldwide, gave training, went again to the US to split a system, scramble and remove data, so I became an archiving specialist, did then the authorization for our remaining site. In most rollouts I was the human interface to master data, then I loaded the master data myself for all modules and now I became MDM teamlead for a system merger project. Somewhere in between I had changed the locality and did SD and transportation.
Others which started almost together with me have been department heads for many years already, it was never my goal. But in whatever I did: I liked it and I cared.
I think this path is no longer possible today and not really wanted in big companies, the HR guys and IT leads want you to fit into a certain box, put the lid on and thats it. if you fit in several boxes then you are just creating a headache for them. On the other hand you are most welcome for Small Company Solutions, implementing SAP somewhere in the world with a team of just 5.