Problem in search filter, when using show field condition in searchfilter plugin

Hi,

I am using filter custom fields and taxonomies plugin to add search filter for custom fields on my site. The plugin is great. But I am having problem in search filter when using it with show filed condition.

The search process is as follows:

For example:- At the starting only vehicle filed is displayed on the right sidebar for search.When user selects vehicle say audi, model filed(it has condition, show field when vehicle=audi) appears on the screen so that user can select model. Once user selects model, an engine filed(it has condition, show field when model=”some value”) appears on the screen and enables user to select engine.
Then search result will be displayed on the right sidebar below search widget and when user clicks on the title, they will be redirected to the individual listing.

It works fine. But now when users selects Another vehicle say ford then previous engine filed remains there which suppose to be displayed for audi only and when user selects model then 2 engine fields are displayed on the screen.

Please help how can I show only one engine field which should be displayed for ford and hide the previous one(which is set to be displayed when vehicle is audi).

Plugin link:
https://wordpress.org/plugins/filter-custom-fields-taxonomies-light/

Site Link:
http://tjkhara.com/kdmc/wordpress/Project-paulcythe/

Thanks in advance.