PE fund of Fund

Does anybody knows/work for a Private equity fund of fund ?

What are the main differences with normal PE funds ?

About working there, does it differ from a PE fund in terms of investment management etc ?
In other terms would it be more vauable/lucrative to work for a PE fund or a PE fund of fund ?

Let's say the fund is 2.2 bn € big, how big is it compared to giants like KKR/Blackstone etc ?