I assume from your post image that you are using the Classic forms designer. You can add images to your form and use rules to show and hide the images.

Below is an example of how to do this.

1. Add a Choice control on the form.

• Name = Status
• Display format = Option buttons
• Choices = Pending, Approved, Rejected

2. Add an Image control to the form.

• Name = Green
• Image URL = https://www.pngfind.com/pngs/m/2-29412_green-light-icon-green-traffic-light-icon-hd.png (or the image you would like)
• Alternate text = Green Light

3. Add a Rule to the Green image control.

• Name = Hide Green
• Rule Type = Formatting
• Condition = not(equals(Status,'Approved'))
• Check the “Hide” box
• This rule will hide the Green image until the “Approved” option is selected in the Status control.

4. Repeat Steps 2-3 for the Pending and Rejected status images.

5. You will need to stack the image controls right on top of one another for them to appear in the same spot.

Bamaeric, thank you for you’re reply. 

I am sorry I was unclear is my original post.

The problem I am facing is how to make the condition dependent on a field in a SharePoint list.

In a workflow a can retrieve this field and use its contents, but I am unaware of any way to retrieve the value of a SharePoint list field for use inside a nintex form.

Do you have any suggestion for this?

Hi @Arnie0071 

@bamaeric has answered your question.
All you need to do is to have a field on the form and that field must be connected to the SharePoint list.

The form will display the field and its value.
The form rules will utilize the value and trigger the appropriate action.

Summary: Just place the connected field to the form. Then apply the rules.

Thanks both of you for your support figured it out, finally.

I was looking in the wrong section I was to connect look via a SharePoint element.

Didn’t know about the lookup function in calculated field.

Made the connection with: lookup(List_Vergaderzaal_133,"Titel",07:00,"Bezet") in a calculated field.

The rest was standard.

By the way in nintex form designer no syntax is given for the lookup function in the calculated field. Figured it out via google. If nintex could give the syntax as it does with other functions (and(boolean1, boolean2)) this would help.