If I understand correctly, you have a picklist field included in a template (on a field editor). When the user clicks on the template they get a popup where each field in the template can be edited. In this scenario, when the user clicks on the template to open the popup and edit the picklist field - you want to do some customization of the picklist values available.
If this is the case - you should look at the template properties. Its “edit mode behavior” should be set to “Show custom popup” In this popup you can have full control over the fields - using custom renderers that manipulate the options provided.
I have a pure html dropdown in the skuid template. which contains the above mentioned code snippet, and I want to access this field from a javaScript and add s dynamically such as,