We did the following steps:

•We have 2 databases

–One company is called MFGCMSA, we are going to use this company as the demand company.

–Physical database name mfgprod, logical name mfgprod.

–Domain MFGCMSA

–The supply company is called Magnekon.

–Physical database name qadmagne, logical name qadmagne.

–Domain MFGMAGNE

•Both companies uses the connection database option 36.6.1

In Demand Company CMSA :

We setup in the 36.6.1 the connection data for the database "MFGMAGNE" and in the option 1.1.13, we setup

the site for the domain "MFGCMSA". After that in the multi-domain processing frame, for the flag: "update", we put the value "yes" for the Domain  "MFGMAGNE"

For  the supply company "MFGMAGNE", We setup in the option 36.6.1, also we add the connection data for the database  "MFGCMSA" and in the option 1.1.13. We setup the site "MFGMAGNE". In the multi-domain processing frame,  for the flag: "update", we put the value "yes" for the Domain MFGCMSA

After the creation of both sites, each in every database, I can see the following in domain "MFGCMSA", receiving site from  "MFGMAGNE" with type: "Connection" and the Domain "MFGCMSA" has type: "Primary"

But this is only in MFGCMSA database, We don't known how to replicate to "MFGMAGNE" database?

We can't find anything else in the manuals: MasterData_UG_2011_1EE.pdf and SupplyChainMgmt_UG_v2011_1EE.pdfSupplyChainMgmt_UG_v2011_1EE.pdf 
thanks in advance