Visibility Of Transaction based on User groups

We are trying this approach to transactions visibility based on User groups,
results = "";
bu = businessUnitId_t;
company = _system_company_name;
pp = _system_current_pp_name;
groups = lower(_system_user_groups);

// Condition 1 – tSCD group
if ( (find(groups, "tscd") >= 0)
AND NOT isnull(bu)
AND (bu == "300000003983302" OR bu == "300000003983299") )
{
results = results + _system_user_login+ "~" + company + "~" + pp;
}

// Condition 2 – sSD group
if ( (find(groups, "ssd") >= 0)
AND NOT isnull(bu)
AND (bu == "300000003983293" OR bu == "300000003983296") )
{
if (results <> "") {
results = results + "|";
}
results = results + _system_user_login + "~" + company + "~" + pp;
}

return results;
we tried this BML AFR in Inprogress step by creating participant profile, it is running without any error but the users of other group can able to see the all the transactions.