No; the underlying technology FoE is based on only supported two-node replication, in addition you can only have one NPM application server active in the database at once.
What are you trying to achieve?
I'm trying to acheive an environment with two hot/warm-standby NPM servers so that if Site A and Site B go down, I can still use Site C which will have up-to-date information (not just via SQL DB replication, but also NPM server information). Has no client of Solarwinds ever requested more than one redundant NPM server in their production networks?
Without any further information I would propose:
1. Use FoE for site A to B resilience. This will provide automatic failover support with zero touch configuration in event of failover event
2. Use a manually driven procedure to provide the 3rd site redundancy. There are a number of ways of dealing with this. Our experience is that our customers have different views on what is suitable for them.
Don't forget about SQL Server, as this will be a critical component of your architecture to get right.