There is no reason for any of this at all.
Your component player_movement
is of type MonoBehaviour
which is a Behaviour
which is a Component
and therefore already has the inherited property transform
returning the Transform
reference if the GameObject
your component is attached to.
So whoever has a reference to your component immediately also has access to its .transform.position
anyway.
As to how get that reference, there are thousands of different ways. The most typical ones
public player_movement playerMovement;
simply drag and drop it in vis the Inspector.
On another component attached to the same GameObject
use
var playerMovement = GetComponent<player_movement>();
or if there is only one in the scene anyway
var playerMovement = FindObjectOfType<player_movement>();
either way in the end as said you can simply use
var playerTransform = playerMovement.transform;
and do with it whatever you want like accessing its position
var playerPosition = playerTransform.position;