how to check if user exist in two groups rest api

You could either do a foreach-statement to check multiple groups (one at the time) or to it the other way around - get a users group membership and then loop through the results.

The user Vadim Gremyachev has added an excellent answer of to handle this here: Get the group of the current user using REST API

I'm quoting his full answer here:

The following example demonstrates how to determine whether current users belongs to the specified groups:

getCurrentUserWithDetails()
.done(function(data)
{
    var groupNames = ['News Owners','Approvers'];
    //determine wether current user is a memeber of group(s) 
    var userGroups = data.d.Groups.results;
    var foundGroups = userGroups.filter(function(g){ return groupNames.indexOf(g.LoginName) > -1});

})
.fail(
function(error){
    console.log(JSON.stringify(error));
});

where getCurrentUserWithDetails function is used to get current user with groups:

function getCurrentUserWithDetails()
{
    var endpointUrl = _spPageContextInfo.webServerRelativeUrl + '/_api/web/currentuser/?$expand=groups';
    return $.ajax({
            url: endpointUrl,
            method: "GET",
            contentType: "application/json;odata=verbose",
            headers: {   
             "Accept": "application/json;odata=verbose"
            } 
        });
}

Key points: more optimal from performance perspective since only a single request is submitted to the server

This can be easily achieved through graph Api.

if you want to lists the group which user is member of.

GET https://graph.microsoft.com/v1.0/users/{id}/memberOf

if you want get count of group a user is member

GET https://graph.microsoft.com/v1.0/users/{id}/memberOf/$count

You can find further details on this referring below Microsoft docs

• List memberOf

Can be acheaved by REST API too,

get the all groups that user belongs to:

"/_api/web/GetUserById(" + userId + ")/Groups"

in function:

GetUserGroups = function(userId){
    var Id = _spPageContextInfo.userId
    if (typeof userId != 'undefined' && userId!=""){
        Id = userId;
    }
    var result = [];
    $.ajax({
        url: _spPageContextInfo.webAbsoluteUrl + "/_api/web/GetUserById(" + Id + ")/Groups",  
        method: "GET",   
        async:false,
        headers: {
            "Accept": "application/json; odata=verbose",
            "Content-Type": "application/json;odata=verbose",
        },
        success: function(data){
            result = data.d.results
        }
    })
    return result;
}