Shortest Path Queries - Query language

Documentation
5

You can store the nodes in the variable which matches the filter and then use that variable in from: and to:

Edit:
Here is the query example:

{ 
  var(func: eq(name, "A")){
   SOURCE as uid
  }
  var(func: eq(name, "L")){
   TARGET as uid
  }  

  path as shortest(from: uid(SOURCE), to: uid(TARGET)) {
    friend
  }
  
   path(func: uid(path)) {
    name
   } 
}