Multiple dropdown filters interfering with each other
If your goal is to filter by one drop-down value at a time then you could use an if statement to check if the passed value is set for each drop-down.  This will only work if each drop-down has an option that is blank or it submits on select so that the other drop-down is not set.

{% set query = "" %}
{% if craft.request.getParam('country1') and 
      craft.request.getParam('country1') is not empty %}
    {% set query = craft.request.getParam('country1') %}
{% elseif craft.request.getParam('development1') and 
          craft.request.getParam('development1') is not empty %}
    {% set query = craft.request.getParam('development1') %}
{% endif %}

{% for category in queryFilter %}

....markup...

{% endfor %}