Vitamin B complex is a group of 8 B Vitamins. Each of these essential vitamins contributes to our overall bodily function. Infographic to understand those role, followed by food sources for each Vitamin.
Note: B7 or Biotin is missing from the list.

Vitamin B5 or Pantothenic acid sources:

Vitamin B3 or Niacin food sources:

Vitamin B2 or Riboflavin food sources:

Vitamin B6 or pyridoxine food sources:

Vitamin B1 or Thiamine food sources:

Vitamin B12 or methylcobalamin food sources: (Non veg and vegetarian sources)

Vitamin B9 or Folate food sources: