Navigation using LINK FIELD and WITH not working

Can you post your full code?  If so, please use the insert -> code functionality to create a code box which will keep your reply to a reasonable size and retain formatting.

load(
  local!test,
  local!action_txt,
  local!action,
  local!imageSize: "FIT",
  local!masterDatasubset,
  local!pagingInfo: a!pagingInfo(
    startIndex: 1,
    batchSize: 20
    /*sort: a!sortInfo(*/
      /*field: "id",*/
      /*ascending: false*/
    /*)*/
  ),
  with(
      local!masterDatasubset:
      if(local!action_txt="CLICK_HERE",
      rule!POC_Report(),{}),
  a!formLayout(
    
        contents: {
          
                    
              
                a!imageField(
                  images: {
                    a!documentImage(
                      document: cons!POC_IMG,
                      link: a!submitLink(
                        label: "CLICK_HERE",
                        value: "CLICK_HERE",
                        saveInto: {
                          local!action_txt
                          
                        }
                      )
                    )
                         
                  },
                  size: local!imageSize
                )
              
            }
          )
        
        
      )
     
      
      )

Here you are

.

Note --> POC_Report is a report created using Report Builder.

So you're setting the value of your local variable, local!masterDataSubset, to whatever is returned by rule!POC_Report... but it looks like you're never actually using local!masterDataSubset in your interface.

Also, i'm unclear why you have local!masterDataSubset defined in your load() and then again in your with()... if it doesn't give you an error outright, anything inside the with() will just reference the with() version of the variable and ignore the load() version, making the load() version useless.

So, what should be the correct way of coding this?

It depends on what you're doing inside rule!POC_Report... if it's returning a dictionary of data or thereabouts, you need to add a component to display its data inside the contents: parameter of your a!formLayout (such as a grid); but if that rule is actually an interface itself, then you would need to move it out of the with() variable and into the formLayout's contents, wrapping it in the same "if" logic there.

It’s a report interface built using a report builder.  

Then you probably need to try the second option I suggested.

Edit: please try the structure I've prepared here - it's your original code as above but with some unnecessary stuff commented out (like the entire with() statement since it's unnecessary at the moment), and the report rule called appropriately inside the formLayout contents.

Please also note that rule!POC_Report will need to only contain elements that are allowed to be nested within the contents of a!formLayout, such as a section, box layout, or individual component or array of components.  If, for example, the rule contains its own a!formLayout for some reason, i would expect you'll get an error when trying my code.

load(
  local!test,
  local!action_txt,
  local!action,
  local!imageSize: "FIT",
  /*local!masterDatasubset,*/
  local!pagingInfo: a!pagingInfo(
    startIndex: 1,
    batchSize: 20
  ),
  
  /*with(*/
    /*local!masterDatasubset: if(*/
      /*local!action_txt="CLICK_HERE",*/
      /*rule!POC_Report(),*/
      /*{}*/
    /*),*/
  
    a!formLayout(
      contents: {
        a!imageField(
          images: {
            a!documentImage(
              document: cons!POC_IMG,
              link: a!submitLink(
                label: "CLICK_HERE",
                value: "CLICK_HERE",
                saveInto: {
                  local!action_txt
                }
              )
            )
          },
          size: local!imageSize
        ),
        
        if(
          local!action_txt="CLICK_HERE",
          rule!POC_Report(),
          {}
        )
        
      }
    )
  /*)*/
)