qmk_firmware/keyboards/thevankeyboards/bananasplit/keymaps/default/keymap.c

#include QMK_KEYBOARD_H

#define DEFAULT_LAYER 0
#define LAYER_1       1

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
  [DEFAULT_LAYER] = LAYOUT_base(
    KC_ESC, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_MINS, KC_EQL, KC_BSPC,
    KC_TAB,  KC_Q,   KC_W,   KC_E,   KC_R,   KC_T,   KC_Y,   KC_U,   KC_I,   KC_O,   KC_P,   KC_LBRC, KC_RBRC, KC_BSLS,
    KC_CAPS,   KC_A,   KC_S,   KC_D,   KC_F,   KC_G,   KC_H,   KC_J,   KC_K,   KC_L,   KC_SCLN,   KC_QUOT, KC_ENT,
    KC_LSFT,   KC_Z,   KC_X,   KC_C,   KC_V,   KC_B,   KC_N,   KC_M,   KC_COMM, KC_DOT,  RSFT_T(KC_SLSH),  KC_UP, _______,
    KC_LCTL,  KC_LGUI,  KC_LALT, KC_ENT,      MO(LAYER_1),      KC_SPC,  KC_RALT, KC_RCTL,  KC_LEFT, KC_DOWN, KC_RIGHT
  ),

  [LAYER_1] = LAYOUT_base(
    _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
    _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
    _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
    _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
    _______, _______, _______,          _______, _______, _______,          _______, _______, _______, _______, _______
  ),
};