Hi;
From reading this post, i am guessing the purpose is to have the SBC and AMM setup a chain of trust based upon a common Certificate Authority.
The SMGR is a Certificate Authority, so can sign a CSR generated on the SBC.
For the chain of trust to be completed, you will need to generate a CSR on the SBC, then have the SBC CSR signed by the SMGR CA.
Then you will load the SMGR CA onto the SBC, then load the signed SMGR SBC CSR onto the SBC.
Once this is done, you setup your links from SBC to AMM, with a TLS profile on the SBC that utilises the SMGR as the CA, and the signed certificate.
Then when the SBC and AMM attempt to communicate, as they both TRUST the Root CA of SMGR, they will trust each other.
Hope this help.
Thanks.