Add new Additional Filters (created this week or month) to leads In Perfex CRM

I am trying to add a new additional filter for leads i


the default additional filters in the leads is:

Code:

<select name="custom_view" title="<?php echo _l('additional_filters'); ?>" id="custom_view" class="selectpicker" data-width="100%">
    <option value=""></option>
    <option value="lost"><?php echo _l('lead_lost'); ?></option>
    <option value="junk"><?php echo _l('lead_junk'); ?></option>
    <option value="public"><?php echo _l('lead_public'); ?></option>
    <option value="contacted_today"><?php echo _l('lead_add_edit_contacted_today'); ?></option>
    <option value="created_today"><?php echo _l('created_today'); ?></option>
    <?php if(has_permission('leads','','edit')){ ?>
    <option value="not_assigned"><?php echo _l('leads_not_assigned'); ?></option>
    <?php } ?>
    <?php if(isset($consent_purposes)) { ?>
        <optgroup label="<?php echo _l('gdpr_consent'); ?>">
            <?php foreach($consent_purposes as $purpose) { ?>
            <option value="consent_<?php echo $purpose['id']; ?>">
            <?php echo $purpose['name']; ?>
            </option>
            <?php } ?>
        </optgroup>
    <?php } ?>
</select>

So what I am trying to do is adding (created this week and this month) in the additional filters. The HTML code its ok. I added this:

Code:

<option value="created_this_week"><?php echo _l('created_this_week'); ?></option>
    <option value="created_this_month"><?php echo _l('created_this_month'); ?></option>

Please any one can help me to get this options working

But really I don't know where can I find the PHP function to add query when I check the select element to Created This week, how can I get the leads in this week or month. and where can I find the function in the files?

I am searching for Lead Controller and Model I don't find anything.