How to create nested routes with parameters using NestJS

i think you need this?

import {Controller, Get, Param} from "@nestjs/common";

@Controller('accounts/:account')
export class TestController{

    @Get('resource2/:someParam/whatever')
    arsPW(@Param('account') account, @Param('someParam') someparam){
        console.log(':account/resource2/:someParam/whatever',account,someparam)
        return account+'_'+someparam+'___';
    }

    @Get('resource1/:someparam')
    aRSP(@Param('account') account, @Param('someparam') someparam){
        console.log(':account/resource1/:someParam',account,someparam)
        return account+'_'+someparam;
    }


    @Get()
    getget(){
        console.log('get');
        return 'aaa';
    }

}

Regarding your use case, you might want to take a look at this router module
=> https://github.com/shekohex/nest-router

Following the documentation of this module, you can define your routes like so:

... //imports
const routes: Routes = [
    {
      path: '/ninja',
      module: NinjaModule,
      children: [
        {
          path: '/cats',
          module: CatsModule,
        },
        {
          path: '/dogs',
          module: DogsModule,
        },
      ],
    },
  ];

@Module({
  imports: [
      RouterModule.forRoutes(routes), // setup the routes
      CatsModule,
      DogsModule,
      NinjaModule
      ], // as usual, nothing new
})
export class ApplicationModule {}

Of course, the routes would be defined in a separate file like routes.ts

Given the fact you have a controller by module, the previous code would end in the following tree of routes:

ninja
    ├── /
    ├── /katana
    ├── cats
    │   ├── /
    │   └── /ketty
    ├── dogs
        ├── /
        └── /puppy

Example: If you want to reach the ketty controller's routes, you will need to reach this endpoint:
<your-api-host>/ninja/cats/ketty

Update This approach is outdated today if you using NestJs v8.0.0 or later, as the documentation of nest-router tells us it's now included on @nestjs/core

and also as pointed by @yehonatan yehezkel, you can follow the documentation for the recommended approach at here https://docs.nestjs.com/recipes/router-module

Parent controller :

@Controller('accounts')
export class AccountsController {
  // http://api.domaine.com/accounts
  @Get()

Child controller :

@Controller('accounts/:id')
export class ResourcesController {
  // http://api.domaine.com/accounts/1/resources
  @Get('resources')

you can simply do this

@Controller('trainer/:trainerId/heroes')
 export class HeroesController {
    constructor(private readonly heroesService: HeroesService) {}

    @Get(':id')
    findOne(@Param('trainerId') trainerId:string,@Param('id') id: string) {
       return `This action returns a #${id} hero trainer id ${trainerId}`;
    }

 }

the uri is:

http://localhost:3000/trainer/4/heroes/5

thr result is

This action returns a #5 hero trainer id 4