git Sparse Checkout.

sparseCheckout.sh

#!/usr/bin/env bash

# Copied from:
# https://github.blog/2020-01-17-bring-your-monorepo-down-to-size-with-sparse-checkout/

% git clone --no-checkout https://github.com/derrickstolee/sparse-checkout-example --depth 1
% cd sparse-checkout-example/
% git sparse-checkout init --cone
# git sparse-checkout init to skip top level files.

% git sparse-checkout set <DIR1> <DIR2>
# git co <BRANCH>