There are many diversity and inclusion groups becoming more popular. They do a lot of good in the community. Can a Christian participate through work with this organization, such as community trash clean-up, knowing they support LGBTQ?
The question you need to ask yourself is whether your participation tells others that you support sinful practices, "for we have regard for what is honorable, not only in the sight of the Lord, but also in the sight of men" (II Corinthians 8:21). We need to be mindful that other people are watching us.
If I'm helping the local community club to give aid to the homeless, then it doesn't matter what other activities the group is involved in. People will remember that you were there to help the homeless. But if you are working for an organization that is known for its support of homosexuality, then there is a problem (I Corinthians 6:9-10).
It comes down to looking at what message you are sending to your neighbors by your participation. There are many good groups out in the world that are not connected to sinful causes. And even if you have trouble finding one, you can always do good on an individual basis or gather a group of co-workers to represent your company in a community effort.