Relationship between Fact to Fact tables

It's usually better to avoid fact to fact joins. If fact_1 and fact_2 are logically related 1 to 1 this means you could inner join them and just create one large "virutal" fact table.

For fact_3 if it is actually a 1 to many relationship what you could do would be to use the join column to copy all the dimension keys from the other two facts down to fact_3 then you would just join the dimensions to the facts and remove the join between fact_3 and the other fact tables. Then any time you filter on one of the dimensions both facts would get filtered.  

google "power bi multiple fact tables" there are several videos on how to easily do this.  We ended up creating a linktable and two fact tables which works good.