Split of salary

 I think YES, the employer's salary can be split and shown in the books of 2 companies, also in the computation of the said employee it can be shown, under the head ' Income from Salary ' as "From Employer A and Employeer B".

where the salary is paid under the obligation of employer and employee relations, an employee can join duty at single employer only, he may offer professional services to others, but employment itself is a full time obligation, so he can not work at simaltenous places more than one.

suppose x is working in a company named "y" and "y" is having tie with "A" and "B" the employer and employee relationship lies only with "X" and "Y" nd hence saliry cannot be split

One way is to show other employment as a part time employment with other company & then split the salary according to proportionate basis..

Agreed.There cannot be multiple employee-employer relations simultaneously.

no we can have multiple employer and employee relationships

Option: 1

The company where employee code is issued and issue the debit note to the other two sister companies for the employee's working. Which is allowed and done in most of the companies.

Option: 2

The employee can work only in one company at a time or work as a part timer in all three companies. In such case he can choose to work as a part timer.

Option: 3

The employee can work as independant consultant and raise the invoice on all three companies.