LED Circuit design (4 switches, 1 potentiometer)
Step 1. Make a truth table.

        LED1  LED2  LED3
Case 1: ON    ON,   OFF 
Case 2: ON    OFF   OFF
Case 3: OFF   OFF   ON (and controlled by a  potentiometer)
Case 4: OFF   OFF   OFF


You should find this easier to read and to convert into a circuit.

Step 2. Decide what a "Case" is.

Edit your question to explain what you mean by "Case". Is it pressing a particular button or what? Also, we need to know what kind of switches they are: how many poles and how many ways (one-way or two-way).