LDAP - Use of wildcard on MemberOf filter

Question

I need to get all users and their groups from a specific category.

Examples of users :

user  | memberof
user1 | CN=group_1,OU=Groupes,OU=CR 1,DC=zcam,DC=ztech
user1 | CN=group_2,OU=Groupes,OU=CR 1,DC=zcam,DC=ztech
user2 | CN=group_2,OU=Groupes,OU=CR 1,DC=zcam,DC=ztech
user3 | CN=group_3,OU=Groupes,OU=CR 2,DC=zcam,DC=ztech

I need to get every user where memberof contains OU=Groupes,OU=CR 1,DC=zcam,DC=ztech (user1 and user2 from my example)

Following this doc (https://learn.microsoft.com/fr-fr/windows/desktop/ADSI/search-filter-syntax) I tried the following syntaxes :

DirectoryEntry ldap = new DirectoryEntry("LDAP://xxx.xxx.xxx.xxx");
using (DirectorySearcher searcher = new DirectorySearcher(ldap))
{
    // Works but return everything
    searcher.Filter = "(&(objectClass=user)(memberof=*))";

    // Works but only for one group
    searcher.Filter = "(&(objectClass=user)(memberof=CN=group_1,OU=Groupes,OU=CR 1,DC=zcam,DC=ztechh))";

    // Doesn't work because searcher.FindAll().Count returns 0
    searcher.Filter = "(&(objectClass=user)(memberof=*,OU=Groupes,OU=CR 1,DC=zcam,DC=ztechh))";

    // searcher.FindAll().Count returns 0
    foreach (SearchResult result in searcher.FindAll()) 
    {
        [...]
    }

Following this (https://community.servicenow.com/community?id=community_question&sys_id=00d29fa1db101fc01dcaf3231f96197f) I tried to change the wildcard * by a % but it didn't changed the result.

Answer 1

Finally I have found another way to do. In fact, this property OU=CR 1 in the memberof correspond to the division in my AD. So I just filter like this :

DirectoryEntry ldap = new DirectoryEntry("LDAP://xxx.xxx.xxx.xxx");
using (DirectorySearcher searcher = new DirectorySearcher(ldap))
{
    searcher.Filter = "(&(objectClass=user)(division=CR 1))";

    foreach (SearchResult result in searcher.FindAll()) 
    {
        [...]
    }

Thanks everyone for your help.