filter method returns empty array

Assuming you cannot edit the original array, you can get object values from it using Object.values().

const STATUS = [{
  0: 'Rascunho',
  1: 'Enviado',
  2: 'Processando',
  9: 'Processado',
  3: 'Agendado',
  4: 'Protocolizado',
  5: 'Suspenso',
  6: 'Erro protocolo',
  7: 'Erro processamento',
  8: 'Erro leitura'
}];

console.log(Object.values(STATUS[0]));

What you most likely want is an enum:

export enum STATUS {
  Rascunho,
  Enviado,
  Processando,
  Processado = 9, // Only these two are needed since enums auto-increment and this one was out of order
  Agendado = 3,
  Protocolizado,
  Suspenso,
  "Erro protocolo",
  "Erro processamento",
  "Erro leitura",
};

export function constantFormatter(params: {
  value: number
}): string {
  return STATUS[params.value];
}

You are trying to access a property that doesn't exist ('params').

You have an array with one object only. And this object doesn't have a params property. params is the variable with the index value. In order to access an object with a variable value, you can't use object.whatever. You have to use object[whatever].

Here:

const STATUS = [{
  0: 'Rascunho',
  1: 'Enviado',
  2: 'Processando',
  9: 'Processado',
  3: 'Agendado',
  4: 'Protocolizado',
  5: 'Suspenso',
  6: 'Erro protocolo',
  7: 'Erro processamento',
  8: 'Erro leitura'
}];

function constantFormatter(params) {
    return STATUS[0][params];
}

console.log(constantFormatter(4));