diff --git a/other/parse_nested_brackets.ts b/other/parse_nested_brackets.ts
new file mode 100644
index 00000000..dce1ef37
--- /dev/null
+++ b/other/parse_nested_brackets.ts
@@ -0,0 +1,47 @@
+/**
+ * @function parseNestedBrackets
+ * @description Parse nested brackets algorithm for a string.
+ * @param {string} text - text to parse
+ * @param {string} openBrackets - open brackets
+ * @param {string} closingBrackets - closing brackets
+ * @returns {string[]} - array of the tags
+ * @example parseNestedBrackets(`<MAIN hoge><MAIN2 fuga>`) => [ '<MAIN hoge>', '<MAIN2 fuga>' ]
+ * @example parseNestedBrackets(
+ *  `THIS IS SAMPLE TEXT(MAIN hoge 0.1 fuga(ITEM fuga hoge)hoge(ITEM2 nogami(ABBR)))`,
+ *  { openBrackets: '(', closingBrackets: ')' }) => 
+ *  [
+      '(MAIN hoge 0.1 fuga(ITEM fuga hoge)hoge(ITEM2 nogami(ABBR)))',
+      '(ITEM fuga hoge)',
+      '(ITEM2 nogami(ABBR))',
+      '(ABBR)'
+    ]
+ */
+ export const parseNestedBrackets = (
+   text: string,
+   openBrackets = "<",
+   closingBrackets = ">"
+ ) => {
+   let array: string[] = []; // The array of the tags in this present floor.
+   let prFloor = 0; // The present floor.
+   let begin = 0, // The begin index of the tag.
+     end = 0; // The end index of the tag.
+   for (let i = 0; i < text.length; i++) {
+     if (text[i] === openBrackets) {
+       prFloor++;
+       if (prFloor === 1) begin = i;
+     } else if (text[i] === closingBrackets) {
+       if (prFloor === 1) {
+         end = i;
+         const tag = text.slice(begin + 1, end);
+         // push the tag in this present floor.
+         array.push(`${openBrackets}${tag}${closingBrackets}`);
+         // push the array of the tags in the next floor.
+         array = array.concat(
+           parseNestedBrackets(tag, openBrackets, closingBrackets)
+         );
+       }
+       prFloor--;
+     }
+   }
+   return array;
+ };
diff --git a/other/test/parse_nested_brackets.test.ts b/other/test/parse_nested_brackets.test.ts
new file mode 100644
index 00000000..751e8651
--- /dev/null
+++ b/other/test/parse_nested_brackets.test.ts
@@ -0,0 +1,24 @@
+import { parseNestedBrackets } from "../parse_nested_brackets";
+
+describe("parseNestedBrackets", () => {
+  it("should return an array of the tags", () => {
+    expect(parseNestedBrackets("<MAIN hoge><MAIN2 fuga>")).toEqual([
+      "<MAIN hoge>",
+      "<MAIN2 fuga>",
+    ]);
+  });
+  it("should return an array of the tags (nested)", () => {
+    expect(
+      parseNestedBrackets(
+        `THIS IS SAMPLE TEXT(MAIN hoge 0.1 fuga(ITEM fuga hoge)hoge(ITEM2 nogami(ABBR)))`,
+        "(",
+        ")"
+      )
+    ).toEqual([
+      "(MAIN hoge 0.1 fuga(ITEM fuga hoge)hoge(ITEM2 nogami(ABBR)))",
+      "(ITEM fuga hoge)",
+      "(ITEM2 nogami(ABBR))",
+      "(ABBR)",
+    ]);
+  });
+});