While there is currently no built-in option to count options that have been selected in a multi-select node, authors can use empty action nodes and number value nodes or calcution action nodes to count selected options in a multi-select node.
Using the braiding technique for multi-select inputs
Whenever authors need to add to an existing value, updating logic is required: a value or action node needs to be introduced containing the start or default value (e.g. '0') and is then updated each time the answer selection contains this specific answer option:
Think of the structure as a braid: only on the strands that indicate that a certain option is contained, the counter value node is updated. To update a value node, authors need to click into the label and choose Update.
Value nodes that are updated will display an arrow symbol to indicate they are linked to a or several nodes of the same name and will overwrite the existing value. To ensure that +1 is always added to the correct base amount, reference the value in itself. This allows carrying over any value that was calculated thus far.
The following video shows how to build such a counter with the braiding technique:
Empty nodes allow authors to circumvent the counter value node in case the option in the multi-select node was not selected. To speed up the process, authors should consider copy-pasting the counter value or action node.
💡 This braiding technique can also be used to calculate risk scores or to display options in a bullet point list for document generation or in content fields using text block values.