If i have a list of 50-60 BT's and Measures and would like to know where those BT's and Measures has been used to create an inventory with list of BT's/Measures to know whether they have been used in Dashboards/Alerts.
So based on your input, to see what particular BTs/Measurements are involved on an alert, you can check the actual incident configuration (should you have permission to view incidents). Also for incidents you can right click and drill down into the purepaths, the purepaths can then tell you what BT's a particular Purepath belongs to, under the details option.
As for dashboards, your best bet would be to view the dashlet properties and see what measures or bt make up the said dashlet. This would give you the direct measure used for a particular dashlet. These methods will take some time I imagine, but this would be the surefire way to correlate measures and BTs to both incidents and Dashboards. Of course you can always take advantage of the measure description field so that any information/notes you have can be retained on the actual measure or business transaction. Hope this helps!