Finding buyers for lower middle market companies?

This question is for those of you that actively seek out buyers and market your clients for sale. How do you get started on the process?

For context, I'm on the valuation and transaction advisory team at an accounting firm. We typically advise clients on the reasonability of offers they receive and conduct DD for M&A. However we just got a client who's motivated to exit and we would like to take this company through the entire deal process. My superiors think this is something we should already be doing, but we have not done it historically.

So how would a typical MM IB go about identifying potential buyers? Names of resources/services or just general advice would be greatly appreciated!