Hide button if selection in Multiple Choice

in the display if  section on the button put something like

MCF = "2" or MCF = "3"

note replace MCF with the name of your multiple choice field

This will show the button if either are selected

you don't say if if it is either option or if both selected

so you may need to fiddle with the script

the numbers are the internal position of the choice field

Just to be clear, are you talking about a regular multiple choice for a dynamic multiple choice?

thomas said:
it's a dynamic multiple choice field

 then you can try something like:

let x := for loop1 in numbers(dMCfield) do
        record(dMC-tableName,loop1)
    end;
count(x[fieldName = "DAF FF 058 PS 2600KG"]) > 0

Lines 1 - 3, here is where we use the for loop to go through the dMC selections and then use the record() function to get the record data from the table that the dMC is based on.

Line 4 then checks the new array of records for the specific value of a field that you use to display in the dMC and if the count of records return is greater than 0 then display.

thomas said:
But what if the name DAF FF 058 PS 2600 KG in the dmc, referenced to the table AUTOCARRO is composed using this formula

 Just treat it like a normal filter:

let x := for loop1 in numbers(dMCfield) do
        record(dMC-tableName,loop1)
    end;
count(x[Marca = XXX and Targa = XXX and Portata = XXX]) > 0

That is benefit of using records. You have access to all of the data. Though I guess it could slow things down if things are too big, but that is another discussion.