Here is a list of intercountry adoptee led groups who include adoptees of any country of origin, based in receiving countries:
Denmark has Adoptionspolitisk Forum
The USA has Land of Gazillion Adoptees, Transracial Eyes, International-Adopt-Talk (includes all members of adoption triad), and PodCast compilation of intercountry adoptee voices at The Rambler. A couple of proactive platforms that include domestic AND intercountry adoptee experiences is Overcoming Odds and Dear Adoption.
Other organisations based in the USA, who have a special focus:
Adoptionland works to politically draw attention to the human trafficking aspect of intercountry adoption and AdopteeRightsCampaign who actively works to bring about legislative change for the estimated 35,000 intercountry adoptees, who currently have no US citizenship.