Hashes as mutually independent keys
The security is considered to be proportional to the size of the keyspace. In your proposal, the keyspace is not increased by adding encryption layers since all keys are derived from a single password.
In the proposed case Hashes are not mutually independent keys since they are derived from a single password. If they are derived from separate password then the algorithm provides three-layered security
Based on the proposal, it can be inferred that the sequence of encryption and the key derivation has to be kept secret for improving security. This is Security through obscurity and is not considered as any stronger. Wiki
If the algorithm is not hidden then cascading encryption with keys derived from the same source is not adding any layers (additional time penalty to brute-force keys at each stage) therefore no better than one layer of encryption, that is the outermost layer.
It provides one layer of encryption with a strength depending on password complexity.