need:
{% for and_filter in filter_and %}
<select name="t_and">
<option></option>
{% for tag in tags | sort %}
<option value="{{tag|e}}" {% if and_filter == tag %}selected{% endif %}>{{tag|e}}</option>
{% endfor %}
</select>
{% endfor %}
<select name="t_and">
<option></option>
{% for tag in tags | sort %}
<option value="{{tag|e}}">{{tag|e}}</option>
{% endfor %}
</select>
<br />
hide:
{% for not_filter in filter_not %}
<select name="t_not">
<option></option>
{% for tag in tags | sort %}
<option value="{{tag|e}}" {% if not_filter == tag %}selected{% endif %}>{{tag|e}}</option>
{% endfor %}
</select>
{% endfor %}
<select name="t_not">
<option></option>
{% for tag in tags | sort %}
<option value="{{tag|e}}">{{tag|e}}</option>
{% endfor %}
</select>