MagicParentsSnippet1

mps1.cls

public static Set<Id> getTopAccountIds(Set<Id> accountsTargeted) {
    Set<Id> topAccountIds = new Set<Id>();
    Set<Id> recursivelyTargetedAccountIds = new Set<Id>();
    for (Account targetedAccount : [
        SELECT Id,
            Name,
            ChildrenUserGroupId__c,
            ChildrenIncludedUserGroupId__c,
            UserGroupId__c,
            ParentUserGroupId__c,
            ParentID,
            Parent.ParentID,
            Parent.Parent.ParentID,
            Parent.Parent.Parent.ParentID

        FROM Account
        WHERE Id IN :accountsTargeted
    ]) {
        if (targetedAccount.Parent.Parent.Parent.ParentID != null) {
            recursivelyTargetedAccountIds.add(targetedAccount.Parent.Parent.Parent.ParentID);
        } else if (targetedAccount.Parent.Parent.ParentId != null) {
            topAccountIds.add(targetedAccount.Parent.Parent.ParentId);
        } else if (targetedAccount.Parent.ParentId != null) {
            topAccountIds.add(targetedAccount.Parent.ParentId);
        } else if (targetedAccount.ParentId != null) {
            topAccountIds.add(targetedAccount.ParentId);
        } else {
            topAccountIds.add(targetedAccount.Id);
        }
    }
    if (!recursivelyTargetedAccountIds.isEmpty()) {
        topAccountIds.addAll(getTopAccountIds(recursivelyTargetedAccountIds));
    }
    return topAccountIds;
}