Let us first get this usage of 「に」 down.
「Person + に + Verb in te-form + ほしい」
means:
"(Someone) wants (Person) to (verb)."
The particle needs to be 「に」 there; No other will work.
So, adding a 「も」 should not make it any more difficult.
「Person + にも + Verb in te-form + ほしい」
thus means:
"(Someone) wants (Person) also to (verb), too."
The "also" modifies (Person) here.
"President Moon would like the North Korean athletes also to participate in the Olympics."
I hope you understand now that it is not possible to translate 「にも」 all by itself.