Accessing step information
The LastCompletedStep() function returns a step object that represents the item’s last completed step. The following are the methods available on the step object that can be referred through by the (.) dot operator.
Returns a list of users to whom the step is assigned directly or indirectly.
Returns the mode of assignment. Possible options can be:
Returns the total number of approvals required in order to complete this step.
Returns the deadline for the particular task
Returns the time at which the step was started.
Returns the list of approver for the step
Here are more articles about expressions: