Feature Request: add all workitems to a swimlane under a certain area path

**Current situation**
I'm using swimmlane definitions like shown in the example at the bottom. This works quite nice. Workitems which have these area paths set can be moved through the swimlanes. It's clear that it is not possible to change the area path via drag n drop, which is also a good behavior to not accidently change the area path.

I have area paths with deeper areas for example Platform\Team1 Platform\Team2 etc. On the board I need to create a swimmlane for every exact area path. Otherwise the Items are not shown or not movable on the board.

**Desired behavor**
On the overall board I only want to see a swimmlane Platform. It should contain workitems which are on any area path beneath that parent area path. I also want to move these items in the swimmlane. That the area path will never be changed on the workitem is a goos behavor and shpuld stay as it is.

**Example**

```
"swimlanes":{
"field":"System.AreaPath",
"defaultValue":"Planning",
"values":[
{
"value":"Planning",
"title":"Planning"
},
{
"value":"Platform",
"title":"Platform"
}
]
},
```