Using Bookshelf Models and knex, How can I fetch data from first table withRelated to second table with a condition of data related to third table

Question

I am using bookshelf with knex query builder. I have 3 sql tables: forms, users, exams and their related models: formsModel,usersModel, examsModel. I am successfully fetching data from forms table with related to exams table as below: at models:

var examsModel = bookshelf.Model.extend({
    tableName: 'exams',
    hasTimestamps: true,
    spf: function () {
      return this.belongsTo("formsModel", "pf_no", "pf_no");
    }
});

at api call:

let query = examsModel.forge();
query = query.orderBy("updated_at", "desc");
const response = await query.fetchPage({
        pageSize: 5,
        page: page,
        withRelated: ['spf']
      });
let responseData = await response.toJSON();

Here in above api call, active users checking is not done.

Now, if I want to add condition such that fetch data of only active users. Then this can also achieved by following code:

data = await examsModel.forge().query((qb) => {
          qb.from('users').innerJoin('exams', 'exams.pf_no', 'users.pf_number')
            .where('users.active', '=', '1')
        })
        .fetchPage({
          pageSize: 5,
          page: page,
    withRelated: ['spf']
        });

But, My working code is very big and I have to replace at lot many places in my code which is very time consuming process and if i want to add some more conditions then again lengthy process.

I want that I dont want to replace existing code, But I should get data by comparing as a active users only. For that we need to make changes in this Bookshelf Model definition. How can I achieve this? I want the solution that makes changes in Model definition such that by making a single file change, It will give me data filtered on basis on third users table?