Assuming the following `yaml`

input file

```
admins:
members:
- john@gmail.com
- peter@gmail.com
viewers:
members:
- maria@gmail.com
- john@gmail.com
```

that is passed to `var.memberships`

via `yamldecode`

, is it possible to produce a list of objects that has the `member`

as `key`

and the groups it belongs to as values, i.e. something like

```
{
"maria@gmail.com" = {
groups = ["viewers"]
},
"john@gmail.com" = {
groups = ["admins", "viewers"]
},
"peter@gmail.com" = {
groups = ["admins"]
}
}
```