How does JS implement the file path of the called function?

Question

Like the title, how to achieve it if possible? The following is the code. The requirement is that it can only be implemented in function foo.

// "/lib/a.js"

export default function foo () {
    // code here
    return path
}

// "/src/pages/b.js"

import foo from "../../lib/a.js"
let str = foo()
console.log(str) // 成功打印本地文件路径

Answer 1

export default function foo () {
    // code here
    return __dirname
}

Answer 2

    // "/lib/a.js"
    
    export default function foo () {
        // code here
        return path
    }
    
    // "/src/pages/b.js"
    
    var str = "../../lib/a.js"
    
    import foo from str
    foo()
    console.log(str) // 成功打印本地文件路径

Please ignore any grammatical errors