I can't really tell if this is significant to the Data Editor, but you all know the medkit and energy pickup items right? Life +25, Life +50, Energy +25, and so forth? Well, it seems that only one unit or hero can pick one of these items up. How do I get this pickups to affect not only one unit but a group of units?
Under the Effects data type the Search Area effect type. Each data type has several subtypes. Each doing different things.
Ok sorry made a mistake the Search Area is what you need. The item unit uses an Ability that is autocast which targets a single unit in an area and uses a set doing the effect desired and suiciding the caster. Add the search after the set.
You currently have a Damage effect selected. You need to create a new effect of the Search Area type. The important fields of that effect are the Search: Areas - Effect, Search: Areas - Radius and Search: Search Filters. Put the Modify Unit under the Search: Areas - Effect and then alter the Set effect you currently have selected in the upper left panel to use the Search Area effect.
The default setup of that item is when a unit comes close enough it autocasts the ability on the single unit. The ability uses a set that does two things. The first is the Modify Unit heal and the second is a Damage effect (the one you are looking at in the picture) directed back at the casting item which kills it. What you are aiming to do with the Search Area effect is make it look for other units within an area and then use the Modify Unit heal.
Like all Set type effects there is an Effect: Effects field that contains a list of other effects that are used simultaneously in parallel by the Set effect. Double click it to open the list and you can alter what effects are in the list. Change the Modify Unit effect to the Search Area effect you have created.