How to make user can only access their own records in odoo?
Providing access rule is one part of the solution. If you look at "Access Control List" in "Settings > Technical > Security > Access Controls Lists", you can see that the group Hr Employee has only read access to the model hr.employee. So first you have to provide write access also to model hr.employee for group Employee. After you have allowed write access to the group Employee for model hr.employee,

Create a new record rule from Settings > Technical > Security > Record Rules named User_edit_own_employee_rule (As you wish).
Provide domain for this group User_edit_own_employee_rule as [('user_id', '=', user.id)]. And this domain should apply for Read and Write. ie; by check "Apply for Read" and "Apply for Write" Boolean field.
Create another record rule named User_edit_own_employee_rule_1
Provide domain for this group User_edit_own_employee_rule as [('user_id', '!=', user.id)]. And this domain should apply for Read only. ie; check "Apply for Read".

Now by creating two record rule for the group Employee, we can provide access to read and write his/her own record but only to read other employee records.
Detail:
Provide write access in access control list to model hr.employee for group Employee. Create two record rule:
User_edit_own_employee_rule :

Name : User_edit_own_employee_rule
Object : Employee
Apply for Read : Checked
Apply for Write : Checked
Rule Definition : [('user_id', '=', user.id)]
Groups : Human Resources / Employee

User_edit_own_employee_rule_1 :

Name : User_edit_own_employee_rule_1
Object : Employee
Apply for Read : Checked
Apply for Write : Un Checked
Rule Definition : [('user_id', '!=', user.id)]
Groups : Human Resources / Employee

I hope this will help you.
I have created groups to give access rights everything seems fine but I want to custom access - rights for module issue. When user of particular group logins, I want that user only able to create/edit their own issue and can't see other users issue.Please help me out!!
Thanks