Is there a folder-specific .bashrc or .bash_profile?

Add this to your ~/.bashrc.

If .bashrc is located in current working directory:

PROMPT_COMMAND='if [[ "$bashrc" != "$PWD" && "$PWD" != "$HOME" && -e .bashrc ]]; then bashrc="$PWD"; . .bashrc; fi'

Depending on your exact use case and constraints, ondir may suit your needs:

ondir is a small program to automate tasks specific to certain directories. It works by executing scripts in directories when you enter and leave them.

It does this by using a central ~/.ondirrc file for per-dir configuration. In contrast, the clever PROMPT_COMMAND setup that @Cyrus suggested allows for the config to reside in the individual directories themselves. Each approach is valid; it depends on the constraints and data you're dealing with.

Disclaimer: I've never used ondir personally. I came across it while looking for an automatic way to handle git user config per-dir. In that case, ondir didn't fit my needs—I ended up using a git alias passing --config options to git clone.

addition from @Cyrus answer, if you use zsh, you need to use precmd() :

PROMPT_COMMAND='if [[ "$profile" != "$PWD" && "$PWD" != "$HOME" && -e .profile ]]; then profile="$PWD"; source .profile; fi'
precmd() { eval "$PROMPT_COMMAND" }

it's answered from this answer

nb: my prompt tests for .profile not .bashrc.